Patient-specific reconstructed anatomies and computer simulations are fundamental for selecting medical device treatment: application to a new percutaneous pulmonary valve

Abstract

Nowadays, percutaneous pulmonary valve implantation is a successful alternative to surgery for patients requiring treatment of pulmonary valve dysfunction. However, owing to the wide variety of implantation site morphology, size and dynamics, only about 15 per cent of cases are suitable for current devices. In order to increase the number of patients who could benefit from minimally invasive procedures, a new valved stent graft for percutaneous implantation has been designed recently. In this study, patient-specific computational analyses have been applied to investigate the suitability of new device designs, using real data from 62 patients who had undergone surgical pulmonary valve replacement. Magnetic resonance images of these patients before surgery were elaborated using imaging post-processing software to reconstruct the three-dimensional volume of each patient's implantation site. Three stent designs were created and tested in these patient outflow tracts using finite-element simulations: stent graft SG1 resembles the first device tested in animals; stent graft SG2 is a custom device tailored for a specific patient morphology; and stent graft SG3 represents a hypothetical larger device. The three devices showed an implantation success rate of 37 per cent, 42 per cent and 63 per cent, respectively. Using patient-specific simulations, we have shown that a percutaneous approach with these new devices may be possible for many patients who are currently referred for surgery. Furthermore, when the new devices become available, the methodologies described may help clinicians in the decision-making process, by enabling virtual implantation prior to the actual procedure.